[Verse 1] Contiguous spread from the sinus, the ear, the tooth, Or hematogenous seeding carrying distant truth, Post-surgical, post-traumatic — four roads to the same address, A capsule forms in stages: cerebritis first, then the abscess. Restricted diffusion glowing on the DWI scan, Ring enhancement, thin medial wall — read the image if you can, Echo the heart, inspect the lung, check every dental root, A right-to-left shunt feeding pus along its hidden route. [Chorus] Aspirate or excise, the capsule tells you which, Empyema needs wide drainage — that delay could be the stitch That unravels everything, so open up the bone, Search the source, run the cultures, six weeks of antibiotics home. Aspirate or excise, restricted diffusion glows, Ring-enhancing, thin medial — follow where the evidence goes. [Verse 2] Subdural empyema — sinusitis lit the fuse, A surgical emergency, you haven't time to choose, Meningitis, ventriculitis, CSF in the balance there, Device-related organisms floating in the ventricular air. Intraventricular vancomycin when systemic can't penetrate, Post-craniotomy osteomyelitis — remove the flap, and wait, Let the wound go quiet, let the inflammation cool, Cranioplasty deferred — that patience is the sharpest tool. [Chorus] Aspirate or excise, the capsule tells you which, Empyema needs wide drainage — that delay could be the stitch That unravels everything, so open up the bone, Search the source, run the cultures, six weeks of antibiotics home. Aspirate or excise, restricted diffusion glows, Ring-enhancing, thin medial — follow where the evidence goes. [Bridge] Now the immunocompromised patient in the bed — A ring-enhancing lesion blooming in their head, Toxoplasma versus lymphoma, cryptococcoma in the mix, Aspergillus threading vessels, mucor doing diabetic tricks. Empiric treatment for toxo first while the workup runs its course, Serologies and CSF India ink, tracing every source, If it fails to shrink in two weeks, the biopsy earns its place — Tumefactive demyelination wearing glioblastoma's face. Neurocysticercosis cycling through its vesicular stage, Racemose form blocking CSF, albendazole plus steroid to engage, Endoscopic removal when the ventricle fills with cysts, Prion disease — autoclave alone won't touch the prion's twists. [Verse 3] HSV encephalitis haunts the temporal lobe, Acyclovir empirically before the MRI probe, The rarest cases swell so hard they need a surgeon's hand — Decompressive craniectomy, an almost unplanned unplanned. Inflammatory mimics wear infection like a coat — Sarcoid, IgG4 pachymeningitis thickening the dura's moat, Autoimmune encephalitis, vasculitis — biopsy, don't resect, The histology illuminates what imaging can't detect. The word for it is *fomite* — any object, cloth, or blade That ferries living pathogen through the choices that you've made, Skin prep, prophylaxis, keep the implant off the drape, Operative duration tracked — infection has no escape.
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